The invention generally relates to an intramedullary nail. Particularly, the invention relates to a locking hole arrangement provided at a non-driving end portion of an intramedullary nail, wherein this end portion of the nail is adapted to be positioned at a distal end portion of a humerus or a tibia, or at a proximal or at a distal end portion of a femur.
In general, the proximal end of the bone is the end of the bone being oriented toward the heart of the human body. The distal end of the bone is the end of the bone being oriented away from the heart of the human body. An intramedullary nail may be a femur nail, a humerus nail or a tibia nail, wherein the intramedullary nail comprises a non-driving end and a driving end. The non-driving end is the end of the nail which firstly enters the intramedullary channel of a bone. Entering the bone from the proximal end of the bone is denoted as antegrade insertion. Entering the bone from the distal end of the bone is denoted as retrograde insertion. Consequently, a nail adapted to be implanted from the proximal end of the tibia may be denoted as antegrade tibia nail, a nail adapted to be implanted from the distal end of the femur may be denoted as retrograde femur nail, a nail adapted to be implanted from the proximal end of the femur may be denoted as antegrade femur nail, and a nail adapted to be implanted from the proximal end of the humerus may be denoted as antegrade humerus nail.
As of today, locking of the non-driven end of intramedullary nails is problematic, namely because of the amount of radiation required during the determination of the position and orientation of transverse locking holes formed within the portion of the intramedullary nail when located in a marrow channel of a bone, to be able to insert locking screws through these holes. Furthermore, it is time consuming and ideally requires well-trained and experienced personal. Therefore, it has a significant influence of the overall operation room time required.
Currently, the situation is the following: A different locking pattern of the non-driving end portion of an intramedullary nail exists for each one of different nails, e.g. humerus, tibia, femur nails. Locking of the non-driving end portion of an intramedullary nail is performed mostly freehand.
U.S. Pat. No. 6,547,791 B1 discloses a tibia nail for retrograde implantation, comprising a tube with a continuous longitudinal bore and including a first anchoring portion with several cross-bores at its non-driving end portion, an adjoining connecting portion, a shank and a second anchoring portion at its driving end portion. The arrangement of the cross-bores permits to fix several fragments at their positions in the region of the tibia plateau, i.e. at the proximal end portion of the tibia.